Loubele M, Bogaerts R, Van Dijck E, Pauwels R, Vanheusden S, Suetens P, Marchal G, Sanderink G, Jacobs R
Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium.
Eur J Radiol. 2009 Sep;71(3):461-8. doi: 10.1016/j.ejrad.2008.06.002. Epub 2008 Jul 18.
To compare the effective dose levels of cone beam computed tomography (CBCT) for maxillofacial applications with those of multi-slice computed tomography (MSCT).
The effective doses of 3 CBCT scanners were estimated (Accuitomo 3D, i-CAT, and NewTom 3G) and compared to the dose levels for corresponding image acquisition protocols for 3 MSCT scanners (Somatom VolumeZoom 4, Somatom Sensation 16 and Mx8000 IDT). The effective dose was calculated using thermoluminescent dosimeters (TLDs), placed in a Rando Alderson phantom, and expressed according to the ICRP 103 (2007) guidelines (including a separate tissue weighting factor for the salivary glands, as opposed to former ICRP guidelines).
Effective dose values ranged from 13 to 82 microSv for CBCT and from 474 to 1160 microSv for MSCT. CBCT dose levels were the lowest for the Accuitomo 3D, and highest for the i-CAT.
Dose levels for CBCT imaging remained far below those of clinical MSCT protocols, even when a mandibular protocol was applied for the latter, resulting in a smaller field of view compared to various CBCT protocols. Considering this wide dose span, it is of outmost importance to justify the selection of each of the aforementioned techniques, and to optimise the radiation dose while achieving a sufficient image quality. When comparing these results to previous dosimetric studies, a conversion needs to be made using the latest ICRP recommendations.
比较锥束计算机断层扫描（CBCT）在颌面应用中的有效剂量水平与多层螺旋计算机断层扫描（MSCT）的有效剂量水平。
估算了3台CBCT扫描仪（Accuitomo 3D、i-CAT和NewTom 3G）的有效剂量，并与3台MSCT扫描仪（Somatom VolumeZoom 4、Somatom Sensation 16和Mx8000 IDT）相应图像采集协议的剂量水平进行比较。使用置于Rando Alderson体模中的热释光剂量计（TLD）计算有效剂量，并根据国际辐射防护委员会（ICRP）103（2007）指南进行表述（与之前的ICRP指南不同，包括唾液腺单独的组织权重因子）。
CBCT的有效剂量值范围为13至82微希沃特，MSCT为474至1160微希沃特。Accuitomo 3D的CBCT剂量水平最低，i-CAT最高。
即使对MSCT应用下颌骨扫描协议，其成像的剂量水平仍远低于CBCT协议，与各种CBCT协议相比，MSCT的视野较小。考虑到如此大的剂量跨度，合理选择上述每种技术并在获得足够图像质量的同时优化辐射剂量至关重要。将这些结果与之前的剂量学研究进行比较时，需要根据ICRP的最新建议进行换算。
